Jet propulsion



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VAvr-reuma! June 3, 1947. 1 R. c. MOLLOY 2,421,518

JET PBnPULsIoN Filed July 5., 1940 2 Sheets-Sheet 2 Al@ .c mmssson A .v runt TRAP 74 cum/tran SUPERCWAHGEH INVENTOR ATTURNEY YRichard CMoIloj/ Patentedllune 3, 194'] Y Richard o. Molloy, Giusto to AUnited Aircraft .Corporation, East Hartford', l

Conn., a.` corporation of Delaware `Application Julyy 5,1940, serial No. 343,993 l This invention relatesto improvements in vehicle power plants and hasfor an' object the pro- `1 claim, `(o1. 17o-135.5) `1 Y of the exhaust-'gases to supercharge the engine,

vision of improved means for utilizing the heatand dynamic energy' of exhaust gases to increase the tractive effort of the power plant.V i

A further object resides in the provision in conl nection with a vehicle power plant of the internal-combustion-engine type of means for-utilii'.- ing the residual energy in the engine exhaust gases for supercharging the engine and adding to the tractive eiTort thereof;

A still further object resides inthe provision in a vehicle power plant including an internal combustion enginefof means for completing the combustion of combustible material in the exhaust gases and utilizing the energy of the exhaust gases to produce a reactive jet for increasing the tractive effort of-the power plant.

Another object residesfin the provision inva power plant 'of the character indicated of means for'utilizing the residual energy of the exhaust` gases for producinga reactive jet to increase the tractive effort of the power plant, and means for injecting additional fuel'and supercharged air into the exhaust ducts to increase the propulsive eiTect of the reactive jet whenever such increased .effect is desired.

full throttle.

Other objects and advantages will be more particularly pointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawings, inv which like complete combustion of the gases, and provide a'rearwardly directed reactive jet, and

.Fig 2 is a` schematic view similar to Fig. l showingmeans'for utilizing the residual energy ofthe exhaust gases to providea rearwardly directed reactive jet and means for increasing the A ,effectiveness of such a. .iet by the addition of fuel and air to the exhaust gases before the gases leave the discharge conduits.

Referring to the drawings in detail andy partic` ularly to Fig. 1, the numeral lll generally indicates an internal combustion enginewhich may bea radial air cooled engine such as is conven-V tionally employed for the propulsion of aircraft although the invention is in no way limited to reference numerals are used to designate similar parts throughout there are shown two slightly different arrangements forY disclosing the inver.'- tion. The drawings, however, are for the purpose of illustration only and are not to be taken as limiting or restricting the invention since itlwill be apparent to those skilled'in the art that various changes inV the illustrated arrangement may he resorted to without in any way exceeding the scope of the invention.

In the drawings:

Fig. 1 is a somewhat diagrammatic view of a vehicle power plant including an internal cornbustion engine and engine exhaust discharge conduits with means for utilizingthe residual. energy any particular type of internal combustion engine. 1 cylinders, one ofwhich is indicated at I2, a drive shaft as indicated at I4, which may drive a proi pulsive mechanism such as an aeronautical pro-V peller, not illustrated, a supercharger diffuser section I6 forA distributing combustible'mixtures to.

the variousfengine cylinders'and exhaust dis-` charge conduits as generally indicated at i8. The exhaust discharge system may include individuall cylinder stacks, one vof which is indicated' at 20, a collector ring as indicated at' 22 and a discharge duct 24ewhichmay lead from the exhaust collector ring to the inlet'oi ancexhaust turbine'26. The turbine Y26 may drive a rotary ,compressoren the inlet 30 of which extends to the exterior of the engine cowl or nacelle, generally indicatedat 32, and the outlet 34 `of which may be connected through an intercooler 36 with the engine carburetor 38 mounted on the engine adjacent to the diiTuser section I6.V `The diffuser section may be connected with the various cylinders byvindividual intake pipes one of which is indicated at 40.

The outlet 42 of the turbine 26 leads into a combustion chamber 44 which terminates in a rear-v wardly directed nozzle 46. The pressure portion of the rotary compressor 2 8 is connected through suitable means such as the outlet 48, conduit 50 and nozzle 5l with the interior of the combustion chamber 44 to force air into the exhaust gases in this combustion chamber so that the air mixing with the lhot exhaust gases from the turbine, outlet will cause combustion of any combustible material remaining in the exhaust gases as they enter the combustion chamber 44. The combustion chamber 44 is so shaped that as the exhaust gases expand due to further combustion and additional heat content there will be a con- Such an `engine may have a plurality of Which sidual energy in the exhaust gases to the tractive l effort produced'by the engine I0.

The speed of the turbine 26 may be controlled by la valve or waste gate 52 disposed between the exhaust duct leading to the turbine intake and a vent duct 54 and the supply lof air from-the compressor 28 to the combustion chamber 44 may becontrolled by a valve 56. pressure relief valve, or a flame or backfire damper B, which may be la check valve opening in the direction of normal gas flow, or a mass of porous heat absorbing material such as metal wool" may be disposed adjacent the compressor connected'end of the conduit 50 to avoid subjecting the compressor tov excessive back pressures or explosiveforces'.

A particular advantage of the arrangement shown in Fig. 1 is that full use can be made of the available heat content of the exhaust gases, whether the fuel-air ratio of the charge in the engine cylinders is purposely high to avoid detonation or not. Ordinarily, as engines are now operated, this available energy in the exhaust gas would be wasted.

In the form of the invention shown in Fig. 2 the exhaust turbine and turbine driven com,- pressor are omitted and the intake air is carried directly to the carburetor 38 through the duct 56. The air delivered to the cylinders is compressed by an engine gear drivensupercharger A portion of this intake air is diverted through the duct 59 and carried to the intake of an auxiliary engine driven compressor 60 the outlet of which is connected through a conduit 62 with a nozzle 614 in the combustion chamber 44 to force an additional supply of air into the exhaust gases flowing through the combustion chamber. .A conduit 66 leads from the carburetor 38 to a nozzle 6B in the duct 62 to inject an additional supply of fuel Vinto the air flowing into the combustion chamber', the supply of fuel through the conduit 66 being controlled by a suitable valve such as is indicated at 10. The airflow through the conduit 62 may be controlled by a suitable valve 12 and a pressure relief valve orflame trap 14 may be provided in the air duct to protect the compressor 60.

With this arrangement the residual heat energy as well as the velocity energy of the exhaust gases are utilized to provide a rearwardly directed jet producing a forwardly directed reactive force on the power plant and the force exerted by this jet is increased by the injection and combustion of additional fuel in the combustion chamber when it is necessary or desired to increase the tractive effort of the engi-ne by this means. In both cases the efliciency of the power plant is materially increased at high airplane speeds by utilizing all of the residual energy of the engine exhaust gases to increase the tractive eifort produced by the engine. The jet producing mechanism including the combustion chamber 44 is maintained within the contour of the cowl or nacelle 32 so that substantially no additional drag will be produced by the inclusion of the jet producing apparatus. A receptacle for the combustion chamber may be provided in the nacelle and this reV ceptaclc may be provided with an air entrance gap 16 and an air'exit gap 18 to provide a stream of lcooling air along the exterior of the combustion chamber.

While two slightly different arrangements have been hereinabove described and illustrated in the accompanying drawings for the purpose of disclosing the invention, it is to be understood that the invention is not hunted to the particular arrangements so described and illustrated but that such changes in the size, shape'land arrangements of the various parts may be resorted to as come within the scope of the sub-joined claim.

Having now described the invention so that others skilled in the art may clearly understand the same, what it is desired to secure by Letters lPatent is as followst In an aircraft powerplant including an linternal combustion engine having fuel and air supplying means for operating said engine -at high power output with an excess of fuel over that required for combustion, an'exhaust manifold for receiving exhaust gas including excess unburned fuel from said engine, an air compressor, an exhaust gas turbine drivingly connected with said air compressor and operativelyconnected with said engine exhaust manifold, an engine driven propeller for producing la propulsiva thrust, and means independent of said propeller for augmenting the propeller thrust, said means comprising; a combustion chamber, a rearwardly directed nozzle -located downstream of said combustion chamber for directing products of combustion from said combustion chamber into the atmosphere as a rearwardly directed gas jet exerting a propul-sive reactive thrust, means for conducting the engine exhaust gas including unburned fuel from said engine through said tur- .bine into said chamber, and means forburning said fuel in said chamber including means for introducing compressed air fromV said air compressor into saidexhaust gas and unburned fuel downstream of said turbine and upstream of said nozzle so as to complete the combustion of said exhaust gas in said .combustion chamber before said gas is ejected from said nozzle, and valvev means for proportioning the quantity of cornpressed air introduced into said exhaust gas and unburned fuel so as to produce a combustibleA mixture of fuel and air in said combustion chamber.

' RICHARD C. MOLLOY.

REFERENCES CITED UNTTED STATES PATENTS Number Name Q Date 1,382,535 OffenV June 21, 1921 2,164,545 Rogers July 4, 1939 958,944 Steward May 24, 1910 2,169,243 Higbie Aug. 15, 1939 2,216,731 Birmann Oct. 8, 1940 2,385,366 Lysholm Sept. 25, 1945 FOREIGN PATENTS Number Country Date 321,933 Great Britain Nov. 19, 1929 696,369 France Oct. 14, 1930 818,703 France June 21, 1937 471,177 Great Britain Aug. 30, 1937 309,273 Italy JulyV 1, 1933 513,751 Great Britain Oct. 20, 1939 454,266 Great Britain Sept. 28, 1936 844,442 France Apr. 24, 1939 

